Flexible mat forming system and method

ABSTRACT

In an exemplary embodiment, a flexible mat forming system includes a rotating drum having a plurality of mold cavities about an outer periphery thereof; a hopper positioned adjacent the drum, the hopper shaped to receive a hardenable paste and deposit the hardenable paste into successive mold cavities of the plurality of mold cavities facing the hopper, as the drum rotates relative to the hopper; wherein the hopper includes an opening shaped and positioned to align with the mold cavities facing the hopper; and a sheet of mesh material that is fed between the hopper and the mold cavities facing the hopper.

TECHNICAL FIELD

The present disclosure relates to systems and methods for formingflexible tied block mats, and more particularly, to systems and methodsfor forming continuous flexible tied block erosion control mats.

BACKGROUND

Erosion is a natural process in which meteorological elements such asrain, wind, and snow remove soil, rock, and dissolved material from onelocation on the Earth's crust and transport it to another location.While such erosion is a natural process, certain localized humanactivity increases the rate of erosion to many times that at whicherosion occurs naturally. Land surfaces adjacent man-made structuressuch as canals, roads, reservoirs and ponds, and artificially createddrainage channels and other waterways are particularly susceptible toerosion because naturally occurring indigenous vegetation is removed inorder to form the structures.

Erosion can be mitigated in these areas by remediation of the landsurface adjacent the canal, road, or channel by planting vegetation toreplace the vegetation that was stripped away during construction.However, there is a time interval between the planting of thereplacement vegetation and the point at which the replacement vegetationis sufficiently developed to prevent further erosion of surface soilduring which further erosion may occur.

Efforts have been made to retain the surface soil in place in theseareas until such time as vegetation can mature to the point where theroot structure of the vegetation retains the soil in place. An exampleof such material is the flexible mat structure disclosed in U.S. Pat.No. 6,793,858 titled “Method and Apparatus for Forming a Flexible MatDefined by Interconnected Concrete Panels,” the entire contents of whichare incorporated herein by reference. That patent discloses a flexiblemat structure in the form of spaced, interconnected concrete panels orblocks held together by an open mesh of a polymeric material.

The flexible mat structure may be made by depositing concrete in theblock-shaped mold cavities formed in the surface of a rotating drum andembedding in the concrete material the open mesh structure. While themethod is effective, there is a need to introduce additionalefficiencies in the manufacture of such flexible mat structure.

SUMMARY

The present disclosure describes a flexible mat forming system andmethod in which improvements have been made to increase the quality ofthe flexible mat product produced and the efficiency in the process ofmanufacturing the flexible mat. One type of mat produced by the processand system is known as a tied block mat, in which blocks of cement arecast in a pattern onto a sheet of geogrid. Such a tied block mat isideal for applying to the ground adjacent airport runways, taxiways andterminals, roadbeds, and the banks of reservoirs, canals, rivers andother waterways, shorelines, and any sloped surface to control erosion.In some embodiments, the system and process produces a tied block matthat is sufficiently sturdy to function as a drivable surface.

In one embodiment, a flexible mat forming system includes a rotatingdrum having a plurality of mold cavities about an outer peripherythereof; a hopper positioned adjacent the drum, the hopper shaped toreceive a hardenable paste and deposit the hardenable paste intosuccessive mold cavities of the plurality of mold cavities facing thehopper, as the drum rotates relative to the hopper; wherein the hopperincludes an opening shaped and positioned to align with the moldcavities facing the hopper; and a sheet of mesh material that is fedbetween the hopper and the mold cavities facing the hopper.

In another embodiment, a method for making a flexible mat includesproviding a plurality of mold cavities; providing a panel having anopening; positioning the panel above the mold cavities and aligning theopening with the mold cavities; placing a sheet of mesh material betweenthe panel and the mold cavities; depositing a hardenable paste throughthe opening and into the mold cavities such that the sheet of meshmaterial becomes embedded in the hardenable paste over the moldcavities; displacing the panel from the mold cavities as the hardenablepaste hardens in the mold cavities into blocks held together by themesh, thereby forming the flexible mat; and removing the flexible matfrom the mold cavities.

In yet another embodiment, a system for making a flexible mat includes aform having a plurality of mold cavities; a panel having an opening; asupport frame for adjustably supporting the panel above the plurality ofmold cavities and aligning the slots adjacent ones of the mold cavities;and the panel is spaced above the mold cavities a distance sufficient toreceive a sheet of mesh material between the panel and the moldcavities.

In still another embodiment, a method for making a flexible mat includesproviding a plurality of mold cavities; providing a panel having anopening; positioning the panel above the mold cavities and aligning theopening with adjacent ones of the mold cavities, wherein positioning thepanel above adjacent ones of the mold cavities includes adjusting aheight of the panel above the mold cavities to a selected spacing;placing a sheet of mesh material between the panel and the moldcavities; depositing a hardenable paste through the opening and into themold cavities such that the sheet of mesh material becomes embedded inthe hardenable paste over the mold cavities; allowing the hardenablepaste to harden into blocks held together by the mesh, thereby formingthe flexible mat; and removing the flexible mat from between the paneland the mold cavities.

Other objects and advantages of the disclosed flexible mat formingsystem will be apparent from the following description, the accompanyingdrawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, side elevational view of an embodiment of thedisclosed flexible mat forming system;

FIG. 2 is a schematic, front elevational view of the flexible matforming system of FIG. 1;

FIG. 3 is a detail perspective view of the flexible mat forming systemof FIG. 1, showing the retaining plate;

FIG. 4 is a perspective view of the flexible mat forming system of FIG.1, taken from the rear of the hopper and drum;

FIG. 5 is a detail showing an embodiment of a rotating auger locatedwithin the hopper of the flexible mat forming system of FIG. 1;

FIG. 6 is a detail perspective view of a section of the hopper of FIG.5;

FIG. 7 is a detail perspective view showing a portion of the bottomplate of the hopper of the flexible mat forming system of FIG. 1; and

FIG. 8 is a perspective view of an embodiment of the cleaning member ofthe flexible mat forming system of FIG. 1.

DETAILED DESCRIPTION

The disclosed flexible mat forming system, generally designated 10, isshown in FIGS. 1, 2, and 4. The system 10 may include a frame 12 onwhich is mounted an elongate, rotatable cylindrical drum 14. The drum 14may be rotated by a motor 16, which in embodiments may be an electricmotor or a hydraulic motor, in which case the system 10 isself-propelled, or assists in propelling itself. The motor 16 may rotatethe drum in a counterclockwise direction, as indicated by arrow A inFIGS. 1 and 4. In other embodiments, system 10 does not have a motor 16,but instead the drum 14 rests on the ground 66 and rotates in thedirection of arrow A as a result of friction with the ground from theframe 12 being pulled over the ground, which in FIG. 1 would be to theleft. In an embodiment, the frame 12 may include a pair of horizontalbeams 18, 20 on which the drum 14 is rotatably mounted, for example by ajournal bearing 17.

As shown in FIG. 4, in an exemplary embodiment, the drum 14 includes aplurality of transverse rows 22 of mold cavities 24 that are formedabout the outer periphery, or cylindrical outer surface, of the drum. Inother embodiments, the mold cavities 24 are arranged in a pattern orpatterns on the drum. In embodiments, the patterns are selected from arectilinear, transverse row of the mold cavities, a staggered pattern ofthe mold cavities, a checked pattern of the mold cavities, a randompattern of the mold cavities, a running bond pattern of the moldcavities, and combinations of the foregoing. With such embodiments, theterm transverse row 22, as used herein, includes any spacing orarrangement or pattern of the mold cavities 24 along the length of theouter periphery of the drum 14, including the aforementioned patterns,and is not limited to a rectilinear row parallel to a central rotationalaxis of the drum 14.

Accordingly, the drum 14, which in embodiments takes the form of anelongated cylinder, is a form having mold cavities 24. In embodiments,the mold cavities 24 may be shaped to receive hardenable paste 25 from achute 27 (see FIGS. 1 and 2) from the drum of a concrete transporttruck, or from a concrete pump, or from a concrete mixer trailer, andform the hardenable paste 25 blocks 76, which in embodiments may besquare at their base. For example, the mold cavities 24 may be shaped toform pyramidal blocks 76 of hardenable paste 25 received from the hopper26 having square bases 6½×″×6½″ and 2¼″ high, although the mold cavitiesmay have other shapes and dimensions. For example, the mold cavities 24may be shaped to form blocks 76 having shapes selected from rectangular,square, hexagonal, octagonal, round, elliptical, irregular, andcombinations of the foregoing.

As shown in FIGS. 1, 2, and 4, the system 10 also may include anelongate hopper, generally designated 26, adjacent the drum 14. In anembodiment, the hopper 26 is positioned directly above the drum at the12 o'clock position, such that the hopper is positioned above anuppermost one of the plurality of transverse rows 22 of mold cavities24. In other embodiments, the hopper 26 is positioned relative to thedrum 14 upstream of the 12 o'clock position, for example at the 2o'clock position, and in still other embodiments, the hopper ispositioned relative to the drum 14 downstream of the 12 o'clockposition, for example at the 10 o'clock position. In other embodiments,the hopper 26 is positioned adjacent the drum 14 in locations betweenthe 3 o'clock position and the 9 o'clock position.

In an embodiment, the hopper 26 is shaped to receive a hardenable paste25 and deposit the hardenable paste into mold cavities 24 facing thehopper. In an embodiment in which the mold cavities 24 are arranged inrectilinear transverse rows 22, the hopper 26 deposits the hardenablepaste 25 along a facing row 28 (see FIG. 7) of the plurality oftransverse rows 22 of mold cavities 24. The hopper 26 may include anopen upper portion 30 having an open top 32 and downwardly extending andconverging front and rear walls 34, 36, respectively. The hopper 26 mayinclude a central section 38 having front and rear walls 40, 42,respectively, shaped to form a trough with an arcuate bottom, and alower section 44 having downwardly and outwardly diverging front andrear walls 46, 48, respectively.

Front and rear walls 34, 36 of the hopper 26 define frontward andrearward facing surfaces, respectively. Side walls 40, 42 define forwardand rearward facing walls, respectively, and walls 48, 46 define forwardand rearward facing walls, respectively. The side walls 34, 36, 40, 42,46, 48 are closed by lateral walls 50, 52 to define an interior chamber54, as shown in FIGS. 5 and 6. In embodiments, the hopper 26 includes abottom panel 122 that in some embodiments is shaped to conform to thecurvature of the outer periphery of the drum 14. As will be described,in embodiments the arcuate shape of the bottom panel 122 may support theremainder of the hopper 26 on top of the drum 14, and in otherembodiments, permit a close spacing between the hopper and the top ofthe drum.

In embodiments, the system 10 includes a support, generally designated56, which takes the form of a spool assembly having a spindle orrotating axle, for supporting a sheet 58 of a mesh material, from a roll60 on the spool assembly 56, between the hopper 26 and the facing row 28(see FIG. 7) of the plurality of transverse rows 22 of mold cavities 24.In embodiments, the spool assembly 56 includes a pair of posts 62 towhich a spindle or axle 63 is attached and extends therebetween. Thesupport 56 may be mounted on a rear platform 64 of the frame 12. In anexemplary embodiment, the rear platform 64 is supported above the ground66 by a pair of rear wheels 68 and a pair of front wheels 70. Inembodiments, the spindle 63 is mounted on the posts 62 for free rotationrelative to the support; in other embodiments the spindle is motorizedto assist in paying out the sheet 58.

The sheet 58 of mesh material may, in an embodiment, be a sheet of openmesh material, and in other embodiments be a sheet of a polymer mesh,which may be a bi-axial geogrid material such as polyester orpolypropylene. An example of such a polypropylene mesh is Fornit 30/30geogrid manufactured by Huesker Inc. of Charlotte, N.C. In anembodiment, the sheet 58 of mesh material may be fed forwardly, that is,to the left in FIG. 1, under guide tube 72, which is mounted on theframe 12 and extends transversely adjacent the drum 14, and either overor under a second transverse guide tube 73, where it continues, passingbeneath the hopper 26 and above the drum 14.

A hardenable paste 25 deposited into the open top 32 of the hopper 26,and in an exemplary embodiment falls downwardly through the hopper andinto the facing row 28 of the plurality of transverse rows 22 where itis retained within the mold cavities 24. In embodiments, the hardenablepaste 25 is a fresh cement paste such as Portland cement, and in aparticular embodiment, is 5000 psi., wet-cast Portland cement. In otherembodiments, the hardenable paste 25 is selected from concrete, amixture of Portland cement, sand, and/or gravel, and a polymer. Thesheet 58 of mesh material becomes embedded in the hardenable paste 25and the combination of mesh and paste continues as the drum 14 rotatesin the direction of arrow A in a downstream direction away from thehopper 26 where the paste hardens and the combination of mesh and pasteleaves the lower portion of the drum 14 as a flexible mat, generallydesignated 74, of blocks 76 of hardened paste material held together bythe sheet 58 of geogrid mesh, also known as a tied concrete (i.e.,hydraulic Portland cement) block mat when concrete is used as thehardenable paste 25. A sheet of such a tied block mat is suitable forapplying to the ground for purposes of erosion control.

As shown in FIGS. 1, 2, 3, and 4, in an embodiment, a retaining plate,generally designated 78, extends partially about the outer periphery ofthe drum 14 and is positioned on the downstream side 80 of the drum andhopper 26. The retaining plate 78 may be spaced sufficiently close tothe outer periphery of the drum to retain the sheet 58 of mesh materialagainst the outer periphery of the drum and the hardenable paste 25within the mold cavities 24 passing between the retaining plate and theouter periphery of the drum 14.

In an embodiment, the retaining plate 78 may be shaped to conform to thecurvature of the outer periphery of the drum 14. Also in an embodiment,the retaining plate may be imperforate, comprising a single sheet ofcurved sheet metal. In other embodiments, the retaining plate 78 is madeof an aluminum alloy, or a woven or nonwoven mat of a geosynthetic, suchas polypropylene, a nylon, other polymers, a polyamide material, orcombinations of the foregoing. In the embodiment shown in FIGS. 1-4, theframe 12 supports the drum 14 and hopper 26, and the hopper ispositioned above an uppermost one of the plurality of transverse rows 22of mold cavities 24. Further, the retaining plate 78 may be attached tothe frame 12.

The retaining plate 78 may include an upper retaining member, generallydesignated 82, that may be attached to the frame 12 for holding an upperportion of the retaining plate 78 against the outer periphery of thedrum 14. The upper retaining member 82 may include an adjustableconnection, which may take the form of adjustable cables or chains 86,88 having ratchets incorporated therein for manually lengthening andshortening their lengths. The adjustable cables or chains 86, 88 mayextend from their upper ends, which may be attached to upright supports90, 92 of the frame 12 and are attached at their lower ends to the upperretaining member 82.

By adjusting the lengths of the cables or chains 86, 88, the spacingbetween the retaining plate 78 and the hopper 26 may be adjusted.Further, the spacing between the outer periphery of the drum 14 and theretaining plate 78 may be varied by adjusting the lengths of the cablesor chains 86, 88. In an embodiment, the upper retaining member 82 maytake the form of an upper retaining bar extending transversely of theretaining plate 78. Another function of the adjustable cables or chains86, 88 is that they may be lengthened or shortened to adjust the heightof the retaining plate 78 above the ground 66. This enables the point atwhich the flexible mat 74 is no longer held against the outer peripheryof the drum 14 and may begin to separate from the drum.

As shown in FIGS. 1-4, the system 10 may include a lower retainingmember 94 that holds a lower portion of the retaining plate 78 againstthe outer periphery of the drum 14. The lower retaining member 94 mayurge a lower edge of the retaining plate 78 against the drum 14 outerperiphery. In an embodiment, the lower retaining member 94 may take theform of a lower retaining bar or a round pipe that extends transverselyof the retaining plate 78. The lower retaining member 94 may includeleft and right adjustment arms 96, 98. The adjustment arms 96, 98 may beattached to the frame 12 and be adjustable in length to vary a forceexerted by the lower retaining member 94 against the shield 78, and thusthe force exerted by the shield against a lower portion of the outerperiphery of the drum 14. The adjustment arms 96, 98 may take the form apair of adjustable straps, each attached to the frame 12.

In embodiments, the lower retaining member 94 may not be attached to theretaining plate 78, but only urged against it, thereby allowing relativeslidable movement between the lower retaining member and the shield, forexample, in response to height adjustment by cables or chains 86, 88. Insuch an embodiment, support chains 97, 99, each extending between andinterconnecting the lower retaining member 94 and the upright supports90, 92 of the frame 12, may support the lower retaining member 94 at apre-set, desired height above the ground 66 and relative to theretaining plate 78.

As shown in FIGS. 1 and 2, the retaining plate 78 may operate to holdthe sheet 58 of mesh material, which in an embodiment may be a geogridor other geosynthetic material, against the outer periphery of the drum14 as the mesh material and rows 22 of mold cavities 24 pass beneath thehopper 26 in a downstream direction, indicated by arrow A, away from thehopper and extend downwardly toward the ground 66. As the rows of moldcavities 24 pass downstream of the hopper 26, they receive a hardenablepaste 25, which in an embodiment may be fresh (i.e., flowable and notyet hardened) cement paste, and the sheet 58 of geogrid mesh materialmay become embedded in the fresh cement paste, and the cement pastehardens as the drum 14 rotates the combination mesh and cement pastebetween the shield 78 and drum 14. At the lowermost portion of the drum14, the paste 25 has hardened, in embodiments at least enough to bedimensionally stable, forming the mesh and block combination 75, alsoknown as a tied concrete block mat, shown in FIG. 1. In embodiments, thepaste 25 is formulated to continue to harden after the paste leaves themold cavities 24 as shown in FIG. 1.

As shown in FIGS. 1, 5, and 6, in an embodiment the hopper 26 includesan auger, generally designated 100, that is positioned in the centralsection 38 of the hopper. The auger 100 may be rotated by a motor 102and functions to distribute a hardenable paste 25, such as fresh cementpaste, along a length of the hopper 26. In an embodiment, the auger 100is co-extensive with the length of the facing row 28 of the plurality oftransverse rows 22 of mold cavities 24. In an embodiment, the auger 100includes a plurality of radially extending protrusions, generallydesignated 104, along its length. In an embodiment, the protrusionsinclude radially extending rods 106 and radially extending paddles 108arranged alternately along a central shaft 110. In an embodiment, therods 106 and paddles 108 extend radially from the central shaft 110 andare spaced about the periphery of the central shaft. In an embodiment,the central shaft 110 may be rotatably mounted in the end walls 50, 52of the hopper 26 (see FIG. 2).

In an exemplary embodiment, the paddles 108 include opposing flatsurfaces 112, 114 that are generally planar in shape and are orientedperpendicular, or generally perpendicular, to a central rotational axisof the shaft 110, which is the same as the central axis of the tubular,rectilinear shaft. The surfaces 112, 114 of the paddles 108, are angledor skewed relative to the central axis of the shaft 110 to displacefresh cement paste deposited in an end of the hopper 26, along itslength, to an opposite end of the hopper when the auger 104 is rotated,for example, clockwise as shown in FIGS. 5 and 6. The rods 106 mayinclude beveled ends 116 angled to provide close clearance with thecurved inner surface of the hopper 26, in contrast to squared or roundedends.

With the auger 100, the hopper 26 may be loaded with cement paste 25 ata loading end 118 (FIG. 2) that may be defined by an enlarged feed chute119. There is no need to distribute hardenable paste 25, such as freshcement paste, along the entire width of the open top 32 of the hopper26. Instead, fresh cement paste may be deposited in only a portion, orin embodiments at a single location, of the hopper 26, for example, intothe enlarged feed chute 119, and the auger 100 is rotated by the motor102 so that the angled paddles 108 rotate in the paste to urge anddistribute the paste along the length of the hopper 26, whereupon itfalls into the mold cavities 24 of the drum 14 through an opening 120.In an embodiment, the opening 120 is formed in the

In an embodiment, the paddles 108 may be distributed along the length ofthe auger 100 and may be attached to the central shaft 110 at regularlyspaced intervals. Also in an embodiment, the paddles 108 may bepositioned along the length of the shaft 110 so that they are alignedwith openings or slots 120 formed in the bottom panel 122 of the hopper26 as shown in FIG. 6. As shown in FIGS. 5 and 6, the paddles 108 androds 106 may arranged in alternating relation along the length of theshaft 110. In other embodiments, the paddles 108 may be angled to urgethe paste from the center of the hopper 26 outwardly to both sides oropposite ends of the hopper. With such an embodiment, paste may bedeposited in a central region of the hopper 26—that is, midway orapproximately midway between the ends 50, 52 of the hopper—and rotationof the central shaft 110 may cause the paddles 108 to urge the pastefrom the center of the hopper 26 to the ends of the hopper. In stillother embodiments, the blades 108 may be angled to urge paste depositedinto the top 32 at any location along the length of the hopper 26, andmay be angled to urge the paste toward the ends 50, 52 of the hopperfrom the point at which the paste is deposited.

As shown in FIGS. 5, 6, and 7, in an embodiment, the hopper 26 includesa bottom panel 122. In an embodiment, the bottom panel 122 has anarcuate shape corresponding to a curvature of the drum 14. In anembodiment, the bottom panel 122 has an opening that takes the form ofspaced slots 120 that extend the length of the hopper 26. In anembodiment, the slots 120 may be shaped and positioned to align with themold cavities 124 of the transverse row 22 of mold cavities (a subset ofmold cavities 24 shown in FIGS. 4 and 8) of the facing row 28 of moldcavities of the drum 14. In an exemplary embodiment, the slots 120 areseparated by dividers 126. In still other embodiments, the slots 120have the same outer dimensions as at least some of the mold cavities 124that come into alignment with them as the drum 14 rotates relative tothe hopper 26. In other embodiments, the opening takes the form of acontinuous, unbroken slot 120 that extends the entire length, orsubstantially the entire length, of the hopper 26 and is co-extensivewith the arrangement of mold cavities 24 (FIG. 2) along the length ofthe drum 14. In still other embodiments, the opening is sized such thatthe slot 120 comprises the entire bottom of the hopper, eliminating thebottom panel 122.

An advantage of placing the slots 120 to align with the mold cavities124 is that the alignment minimizes waste of the fresh cement paste 25that is deposited in the hopper 26 by preventing fresh cement paste frombeing deposited between the mold cavities 124 on the outer periphery ofthe drum 14. As shown in FIGS. 5, 6, and 7, in an embodiment theplurality of slots 120 are arranged in a rectilinear row. In otherembodiments, the slots make a non-linear pattern along, or partiallyalong, the bottom panel 122. Each of the slots 120 may be of the sameouter dimensions as the corresponding mold cavity 124 of the facing rowof the plurality of rows 22 of mold cavities 24 formed on the outerperiphery of the drum 14 that may pass beneath it as the drum 14rotates.

As shown in FIGS. 1, 2, and 4, in an embodiment the hopper 26 issuspended from the supports 90, 92 of the frame 12. As shown in FIG. 2,in an embodiment the system 10 includes adjustable cables or chains 130,132 that are attached to the support frames 90, 92 and extend downwardlyto be attached to the panel 122 in the bottom of the hopper 26. Tomaintain the hopper 26 in position directly above the 12 o'clockposition of the drum 14, in an embodiment the system 10 includesadjustable cables or chains 134, 136, that are attached at their upperends to the upper portion 30 of the hopper 26 and extend downwardly tobe attached at their lower ends to a transverse support beam 138 of theframe 12.

As shown in FIGS. 1 and 4, in an embodiment the hopper 26 is held inposition above the uppermost portion of the drum 14 by adjustable cablesor chains 140, 142 that are attached to posts 144, 146 of the frame 12.In an embodiment, the adjustable cables or chains 140, 142 also arelengthened and shortened to maintain the hopper 26 at the appropriateorientation above the drum 14. The clearance between the bottom surface124 of the hopper 26 and the upper portion of the drum 14 is adjusted byappropriately lengthening or shortening the adjustable chains 130, 132(see FIG. 2). With this structure, the hopper 26 may be suspended fromthe frame 12 to “float” above the upper portion of the drum 14, which inembodiments may be at approximately the 12 o'clock position, or in otherembodiments, rest on the top of the drum 14 with a pre-set amount ofweight force of the hopper.

As shown in FIGS. 1 and 8, the system 10 may include a cleaning member150 that may be incorporated into the guide member 73. The cleaningmember 150 may be positioned adjacent the elongate drum 14 and upstreamof the hopper 26. The cleaning member 150 may include an implement forremoving from the successive ones of the transverse rows 22 of moldcavities 24 a portion of the hardenable paste 25 (e.g., hydraulicPortland cement) that has not separated from the mold cavities to formthe flexible mat 74. The implement may take the form of a plurality ofprotrusions 152 positioned to engage the mold cavities 24 formed in theouter periphery of the drum 14. The protrusions 152 may be flexible andshaped to extend into and scrape the surfaces of the mold cavities 24.

The cleaning member 150 may extend transversely of the drum 14 and maybe positioned downstream of the lowermost position of the rows 22 ofmold cavities 24, which also may be viewed as being positioned upstreamof the mold cavities prior to their passing beneath the hopper 26. Inthe embodiment shown in FIG. 8, the protrusions 152 may take the form ofa plurality of wire cable segments shaped and positioned to scrapesurfaces of the mold cavities 24 of an adjacent one of the plurality oftransverse rows 22 of mold cavities 24. The wire cable segments 152 maybe formed to have frayed outer ends that brush the surfaces of the moldcavities 24 in the manner of a wire brush to remove hardened paste thathas not adhered to the finished geogrid 58 to form the flexible mat 74.In the embodiment 10 shown in FIGS. 1 and 8, the sheet 58 of meshmaterial may be payed out from the roll 60 and extend over the guidemember 73.

The foregoing components of the system 10 for forming a flexible matprovide an efficient operation and minimize the waste produced. Theframe 12 may be moved by a separate device, such as a tractor or truck,so that, as the drum 14 rotates to deposit the finished flexible mat 74,the mat material is laid out on the ground 66 as a continuous sheet. Inan embodiment, as shown in FIG. 1, a tractor 200, which may take theform of a telehandler, may be connected to the transverse support beam138 by a cable 202 connected to a ring 204. In that embodiment, thetractor 200 may pull the frame 12 of the system 10 to the left in FIG. 1over the ground 66, which motion makes the drum 14 rotate in thedirection of arrow A, pulling the mesh material 58 from the spoolassembly 26, under guide tube 72, over second guide tube 73, and betweenthe outer periphery of the drum 14 and the underside of the bottom panel122.

As the sheet 58 of mesh material, shown partially removed in FIG. 6 forclarity, passes beneath the hopper 26, the hardenable paste 25, whichhas been deposited into the hopper 26 and distributed by the auger 100along the length of the hopper, falls through the slots 120 into thecavities 124 (a subset of the cavities 24 shown in FIGS. 4 and 8) tofill the cavities. The sheet 58 of mesh material, which is held againstthe outer periphery of the drum 14 by the bottom panel 122 and thetension of the mesh being payed out from the spool assembly 56 and thepinch between the bottom of the drum and the ground 66, becomes embeddedin the paste held in the cavities 124.

The combination of the sheet 58 of mesh material and paste is heldagainst the outer periphery of the drum 14 and the paste within thecavities 124, 24 as the transverse row 22 of mold cavities 124 rotateforwardly of the bottom panel 122 by the retaining plate 78. By the timethe transverse row 22 of mold cavities 124 rotates beneath the retainingplate 78, the paste has hardened sufficiently to retain its shape as itfalls by gravity downwardly from the mold cavities to the ground 66,forming the flexible mat 74 (FIG. 1). Further hardening of the pasteinto the blocks 76 may occur after the flexible mat 74 has separatedfrom the drum 14 and been laid on the ground 66. The finished flexiblemat 74 may thereafter be rolled up and transported to a desiredlocation, where it may then be unrolled to form an erosion barrier.

After the flexible mat 74 has separated from the mold cavities 24,further rotation of the drum 24 brings the now-empty mold cavitiesupwardly into contact with the protrusions 152 of the cleaning member150, which scrape any hardened paste from the cavities 24 as they passby the cleaning member. The cleaned cavities 24 then again pass beneaththe hopper 26 to be overlaid with mesh material 58 and receivehardenable paste 25 from the hopper 26.

In an exemplary embodiment, the system 10 for making a flexible mat 74includes a form having a plurality of mold cavities 24, a panel 122having an opening 120, and a frame 12 that adjustably supports the panelabove the plurality of mold cavities and aligns the opening withadjacent ones of the mold cavities. The frame 12 spaces the panel abovethe mold cavities 24 a distance sufficient to receive the sheet 58 ofmesh material between the panel 122 and the mold cavities. In theexemplary embodiment shown in FIG. 1, the form is the drum 14 having theplurality of mold cavities 24 formed in its outer cylindrical surface.In embodiments, the opening 120 takes the form of a plurality of slots,as shown in FIG. 6. In embodiments, the panel 122, which is a part ofthe hopper 26, is adjustably supported above the mold cavities 24 of thedrum 14 by adjustable cables or chains 140, 142, and clearance betweenthe bottom surface 124 of the hopper and the upper portion of the drum,and hence the spacing of the panel above the mold cavities, is adjustedby lengthening or shortening the chains 130, 132 as well.

In an exemplary embodiment of the method for making a flexible mat 74using the system as described in the previous paragraph, the pluralityof mold cavities 24, which may be formed on the drum 14, is provided,and the panel 122 having an opening 120 is provided. The panel 122 ispositioned above the mold cavities 24 and the opening 120 is alignedwith adjacent or corresponding ones of the mold cavities. In anembodiment, positioning the panel 122 above the adjacent ones of themold cavities 24 includes adjusting a height of the panel above the moldcavities to a selected spacing between the panel and the mold cavitiesusing the adjusting chains 130, 132 and 140, 142. A sheet 58 of meshmaterial is placed between the panel 122 and the mold cavities 24, and ahardenable paste 25 is deposited through the opening 120 and into themold cavities such that the sheet of mesh material becomes embedded inthe hardenable paste over the mold cavities. The hardenable paste 25 isallowed to harden into blocks 76 held together by the sheet 58 of meshmaterial, thereby forming the flexible mat 74, which in embodimentsconsists of or comprises a tied block mat. The flexible mat 74 is thenremoved from between the panel 122 and the mold cavities 24.

While the methods and forms of apparatus disclosed herein constitutepreferred forms of the disclosed flexible mat forming system, it is tobe understood that the system and invention are not limited to theseprecise forms apparatus and methods, and that changes may be madetherein without departing from the scope of the disclosure.

What is claimed is:
 1. A flexible mat forming system, comprising: arotating drum having a plurality of mold cavities about an outerperiphery thereof; a hopper positioned adjacent the drum, the hoppershaped to receive a hardenable paste and deposit the hardenable pasteinto successive mold cavities of the plurality of mold cavities facingthe hopper, as the drum rotates relative to the hopper; wherein thehopper includes an opening shaped and positioned to align with the moldcavities facing the hopper; and a sheet of mesh material that is fedbetween the hopper and the mold cavities facing the hopper.
 2. Theflexible mat forming system of claim 1, wherein the mold cavities arearranged in a pattern on the drum, the pattern selected from a linearrow of the mold cavities, a staggered pattern of the mold cavities, achecked pattern of the mold cavities, a random pattern of the moldcavities, a running bond pattern of mold cavities, and combinations ofthe foregoing.
 3. The flexible mat forming system of claim 1, whereinthe mold cavities have shapes selected from rectangular, square,hexagonal, octagonal, round, elliptical, irregular, and combinations ofthe foregoing.
 4. The flexible mat forming system of claim 1, furthercomprising a support, wherein the mesh material is fed from the supportto a location between the hopper and the mold cavities facing thehopper.
 5. The flexible mat forming system of claim 1, wherein thehopper includes a bottom panel having an arcuate shape corresponding toa curvature of the rotating drum.
 6. The flexible mat forming system ofclaim 5, wherein the bottom panel includes the opening shaped such thathardenable paste deposited into the hopper flows through the opening tofill mold cavities of the facing row of the plurality of transverse rowsof mold cavities.
 7. The flexible mat forming system of claim 6, whereinthe opening includes a plurality of slots through which the hardenablepaste flows from the hopper to the mold cavities, and the plurality ofslots extends transversely of the hopper.
 8. The flexible mat formingsystem of claim 7, wherein slots of the plurality of slots are arrangedin a rectilinear row.
 9. The flexible mat forming system of claim 7,wherein slots of the plurality of slots have the same outer dimensionsas at least some of the mold cavities.
 10. The flexible mat formingsystem of claim 1, further comprising a frame; and wherein the rotatingdrum is rotatably mounted on the frame, the hopper is positioned on theframe adjacent the drum, and the hopper is suspended from the frame toform a gap between the mold cavities of the plurality of mold cavitiesfacing the hopper a sufficient distance to allow the sheet of meshmaterial to pass between the hopper and the facing row of the pluralityof transverse rows of mold cavities.
 11. The flexible mat forming systemof claim 10, wherein the hardenable paste is selected from a freshcement paste, optionally wet-cast Portland cement, concrete, a mixtureof Portland cement, sand, and/or gravel, and a polymer; and the meshmaterial is a geogrid.
 12. The flexible mat forming system of claim 10,wherein the hopper is positioned above an uppermost one of the pluralityof transverse rows of mold cavities.
 13. A method for making a flexiblemat, the method comprising: providing a plurality of mold cavities;providing a panel having an opening; positioning the panel above themold cavities and aligning the opening with the mold cavities; placing asheet of mesh material between the panel and the mold cavities;depositing a hardenable paste through the opening and into the moldcavities such that the sheet of mesh material becomes embedded in thehardenable paste over the mold cavities; displacing the panel from themold cavities as the hardenable paste hardens in the mold cavities intoblocks held together by the mesh, thereby forming the flexible mat; andremoving the flexible mat from the mold cavities.
 14. The method ofclaim 13, wherein placing a sheet of mesh material includes placing asheet of geosynthetic material between the panel and the mold cavities.15. The method of claim 13, wherein providing a plurality of moldcavities includes providing mold cavities shaped to form pyramidalblocks.
 16. The method of claim 13, further comprising preventing thehardenable paste from being deposited onto the sheet of mesh materialbetween the mold cavities by separating the opening into a row of slotsby dividers.
 17. The method of claim 13, wherein placing a sheet of meshmaterial includes placing a sheet of mesh material between the panel andthe mold cavities and spacing the panel from the mold cavities to holdthe sheet of mesh material against the mold cavities.
 18. The method ofclaim 13, wherein positioning the panel above the mold cavities includesvarying a height of the panel above the mold cavities to a selectedspacing.
 19. A system for making a flexible mat, the system comprising:a form having a plurality of mold cavities; a panel having an opening; asupport frame for adjustably supporting the panel above the plurality ofmold cavities and aligning the opening with adjacent ones of the moldcavities; and the panel is spaced above the mold cavities a distancesufficient to receive a sheet of mesh material between the panel and themold cavities.
 20. A method for making a flexible mat, the methodcomprising: providing a plurality of mold cavities; providing a panelhaving an opening; positioning the panel above the mold cavities andaligning the opening with adjacent ones of the mold cavities, whereinpositioning the panel above adjacent ones of the mold cavities includesadjusting a height of the panel above the mold cavities to a selectedspacing; placing a sheet of mesh material between the panel and the moldcavities; depositing a hardenable paste through the opening and into themold cavities such that the sheet of mesh material becomes embedded inthe hardenable paste over the mold cavities; allowing the hardenablepaste to harden into blocks held together by the sheet of mesh material,thereby forming the flexible mat; and removing the flexible mat frombetween the panel and the mold cavities.